1. Field of the Invention
The present invention relates to an image processing apparatus for processing a document sheet image in accordance with an area specified by a marker marked on the document sheet.
2. Related Background Art
In an existing full color copying apparatus, an area specification by a colored marker has been widely used as a method for user designating an area in a document sheet which is subjected of a specific edit operation.
In this type of apparatus, three color amount signals R (red), G (green) and B (blue) which were read from the document sheet and converted to digital signals are compared with upper limits and lower limits of the R, G and B components of the respective reference markers to determine whether they are within the range of the marker colors or not, and if all of the three colors are determined to be within the range of the marker colors, it is recognized as the marker color and a mark signal is outputted. Based on the mark signal, a specific edit operation is conducted for an edit area (designated area) surrounded by the mark signal as shown in FIG. 16A, or defined by a closed area surrounding the mark signal as shown in FIG. 16B.
In the prior art, however, since the marker is discriminated from other area of the document sheet by the color, when the area is to be specified for a full color document sheet, the area may not be correctly specified if a color similar to the marker is present in the document sheet image.
Further, when the maker overlaps a color of the document sheet image, the area specification cannot be correctly conducted and the color of the document sheet image is also altered. As a result, the application of the area specification by the marker has been limited to a black and white document sheet in the prior art.
It is an object of the present invention to provide an image processing apparatus which solves the above problems.
It is another object of the present invention to provide an image processing apparatus which allows the area specification by a marker for a color document sheet.
It is other object of the present invention to provide an image processing apparatus which allows the area specification by the marker without contaminating a document sheet.
Other object and features of the present invention will be apparent from the following description and the accompanying drawings.